/prog/ - LISP — World4ch

Name: Anonymous 2009-12-01 13:59

hey /prog, could you guys help me with assignment. I need to write a program in Lisp that does
Π((k-a)/(k+a))=((1-a)/(1+a))*((2-a)/(2+a))*...*((n-a)/(n+a)), k=1..n
k, a are read from stdin

Name: Anonymous 2009-12-01 14:15

>>1
jesus fucking christ

Name: Anonymous 2009-12-01 14:18

>>2
Doesn't compile.

Name: Anonymous 2009-12-01 14:22

how do you "do" an equation?

Name: Anonymous 2009-12-01 14:23

you've used k as a loop variable and you said is comes from input.

Name: Anonymous 2009-12-01 14:24

>>4
>>5
No fucking wonder this idiot can't write it herself.

Name: Anonymous 2009-12-01 14:36

"fuck i meant a and n are read from stdin"

Name: Anonymous 2009-12-01 15:54

(defun f (a n)

  (do ((k 1 (1+ k))

       (prod 1 (* prod (/ (- k a) (+ k a)))))

      ((> k n) prod)))

Name: Anonymous 2009-12-01 16:43

(define f

  (λ(a k)

    (/ (- k a) (+ k a))))



(define Π

  (λ(a k)

    (let Pi ((k′ 1)

             (accum (f a 1)))

      (if (= k k′)

          accum

          (let ((k′′ (+ 1 k′)))

            (Pi k′′ (* accum (f a k′′))))))))



(define Π-reader

  (λ()

    (display "k = ")

    (let ((k (read)))

      (display "a = ")

      (let ((a (read)))

        (if (not (and (positive? k) (integer? k) (number? a)))

            'error

            (Π a k))))))



Welcome to DrScheme, version 4.2.1 [3m].

Language: Module custom; memory limit: 512 megabytes.

(Π-reader)

k = 10

a = 1/3

11339/82460

Name: Anonymous 2009-12-01 16:48

(-1)^k * (a! * (a-1)!)/((a+k)! * k!)

Name: Anonymous 2009-12-01 17:12

>>10
You are wrong.

Name: Anonymous 2009-12-01 18:39

>>11
That's possible, maybe I should have written it down.

LISP

Name: Anonymous 2009-12-01 13:59

Name: Anonymous 2009-12-01 14:15

Name: Anonymous 2009-12-01 14:18

Name: Anonymous 2009-12-01 14:22

Name: Anonymous 2009-12-01 14:23

Name: Anonymous 2009-12-01 14:24

Name: Anonymous 2009-12-01 14:36

Name: Anonymous 2009-12-01 15:54

Name: Anonymous 2009-12-01 16:43

Name: Anonymous 2009-12-01 16:48

Name: Anonymous 2009-12-01 17:12

Name: Anonymous 2009-12-01 18:39

Name: Anonymous 2010-11-14 23:55

Name: Anonymous 2012-10-20 15:53

Name: Anonymous 2013-06-18 18:28

Name: Anonymous 2013-06-18 18:35

Name: Anonymous 2013-06-18 18:42

Name: Anonymous 2013-06-18 18:49

Name: Anonymous 2013-06-18 18:55

Name: Anonymous 2013-06-18 19:02

Name: Anonymous 2013-06-18 19:09

LISP

1 Name: Anonymous 2009-12-01 13:59

2 Name: Anonymous 2009-12-01 14:15

3 Name: Anonymous 2009-12-01 14:18

4 Name: Anonymous 2009-12-01 14:22

5 Name: Anonymous 2009-12-01 14:23

6 Name: Anonymous 2009-12-01 14:24

7 Name: Anonymous 2009-12-01 14:36

8 Name: Anonymous 2009-12-01 15:54

9 Name: Anonymous 2009-12-01 16:43

10 Name: Anonymous 2009-12-01 16:48

11 Name: Anonymous 2009-12-01 17:12

12 Name: Anonymous 2009-12-01 18:39

13 Name: Anonymous 2010-11-14 23:55

16 Name: Anonymous 2012-10-20 15:53

17 Name: Anonymous 2013-06-18 18:28

18 Name: Anonymous 2013-06-18 18:35

19 Name: Anonymous 2013-06-18 18:42

20 Name: Anonymous 2013-06-18 18:49

21 Name: Anonymous 2013-06-18 18:55

22 Name: Anonymous 2013-06-18 19:02

23 Name: Anonymous 2013-06-18 19:09

Name: Anonymous 2009-12-01 13:59

Name: Anonymous 2009-12-01 14:15

Name: Anonymous 2009-12-01 14:18

Name: Anonymous 2009-12-01 14:22

Name: Anonymous 2009-12-01 14:23

Name: Anonymous 2009-12-01 14:24

Name: Anonymous 2009-12-01 14:36

Name: Anonymous 2009-12-01 15:54

Name: Anonymous 2009-12-01 16:43

Name: Anonymous 2009-12-01 16:48

Name: Anonymous 2009-12-01 17:12

Name: Anonymous 2009-12-01 18:39

Name: Anonymous 2010-11-14 23:55

Name: Anonymous 2012-10-20 15:53

Name: Anonymous 2013-06-18 18:28

Name: Anonymous 2013-06-18 18:35

Name: Anonymous 2013-06-18 18:42

Name: Anonymous 2013-06-18 18:49

Name: Anonymous 2013-06-18 18:55

Name: Anonymous 2013-06-18 19:02

Name: Anonymous 2013-06-18 19:09